The objectives of this research were to investigate the effectiveness
of iodine as a means of chemical disinfection. and storage treatment
on the removal of E.coli as indicator organisms in polluted water
and to investigate the application of these techniques to the
provision of potable quality water in disaster situations.
To demonstrate the viability. or otherwise of iodine as a means of
chemical disinfection. various concentrations of iodine (0.5 to 10.0
mg/l) were employed to inactivate E.coli as an indicator organism
in low quality waters prepared by adding kaolin. stream sediments.
digested sludge. raw sludge and an artificial suspension of hydrazine
sulphate and hexamethylenetetramine as the sources of turbidity
and total organic carbon (TOe). Five turbidity and TOe ranges.
three temperature levels and three pH values were also employed
during the investigation of iodine disinfection. The results obtained
were compared with those of an arbitrarily selected standard of 1.0
This investigation has demonstrated that under all the conditions
for which dosages of 8.0 mg/l iodine were employed. a water of
virtually potable quality was obtained within a 30 minutes contact
period. except those containing raw sludge of more than 7 NTU.
Under none of the highest inveStigated conditions (350 C. 9.0pH and
93-100NTU) of natural water samples was a dosage of 1.0 mg/l
iodine found to be an effective disinfectant. Both 1.0 mg/l chlOrine
and 2.0 mg/l iodine were generally effective in the samples having
lower TOe values Le. kaolin and stream sediments at all investigated
turbidity. temperature and pH conditions. The above dosages were
also found effective in the samples containing digested sludge at the
lowest investigated ranges of turbidity. temperature and pH (5-
7NTU. 50e and 6.0pH). The diSinfecting capabilities of iodine in
almost all the samples were found to decrease with an increase in
turbidity. TOe. temperature and pH.
An investigation was carried out to demonstrate the effectiveness of
storage treatment by employing low quality water containing 5 and
100 NTU of stream sediments and raw sludge at 50. 200 and 350e
and at 6. 7.5 and 9 pH revealed that the efficiency of this process
increased with the time of storage. Its effectiveness was also found
to depend upon pH and temperature. Two days storage brought
considerable improvement in the quality of water treated at 350C.
Seven days storage inactivated more than 90% E.coli in most of the
samples treated at 200 and 350C. However. for all types of water
employed under all conditions of turbidity. pH and temperature. a
storage of 14 days was needed to remove all E.coli.
A strategy for the treatment of poor quality water in disaster
situations based upon the results achieved from above investigations
was prepared. An algOrithm of the decisions for urgent provision of
water in disaster situations was also produced.
Overall. the results obtained from these investigations indicate the
potential of water treatment by storage and by using iodine as a
means of chemical disinfection in disaster Situations in which only
poor quality water containing a high proportion of organic matter
over a range of pH and temperature values is available.
A Doctoral Thesis. Submitted in partial fulfillment of the requirements for the award of Doctor of Philosophy of Loughborough University.